Answer in brief
CVE-2026-90076 records a Unknown severity vulnerability in net/sched: fq: add overflow bounds to quantum and initial quantum. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=afe4fd062416b158a8a8538b23adc1930a9b88dc <d16dac3925be95ad46e986d4b139c9898b6e227f || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <f6b3e3848a5fca63438984acd6d9eceac80814c1 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <e35acd56f244d94355f9ab237c2ecc8fba5e6f04 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <709f34f7c28dc4dd6c40343d101850f11e172312 | d16dac3925be95ad46e986d4b139c9898b6e227f, f6b3e3848a5fca63438984acd6d9eceac80814c1, e35acd56f244d94355f9ab237c2ecc8fba5e6f04, 709f34f7c28dc4dd6c40343d101850f11e172312 |
| Linux/Linuxgeneric | 3.12 | Not reported |
| Linux/Linuxgeneric | >=afe4fd062416b158a8a8538b23adc1930a9b88dc <fd63409b669f9951f1cc6b02486a5254103800d1 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <d16dac3925be95ad46e986d4b139c9898b6e227f || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <f6b3e3848a5fca63438984acd6d9eceac80814c1 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <e35acd56f244d94355f9ab237c2ecc8fba5e6f04 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <709f34f7c28dc4dd6c40343d101850f11e172312 | fd63409b669f9951f1cc6b02486a5254103800d1, d16dac3925be95ad46e986d4b139c9898b6e227f, f6b3e3848a5fca63438984acd6d9eceac80814c1, e35acd56f244d94355f9ab237c2ecc8fba5e6f04, 709f34f7c28dc4dd6c40343d101850f11e172312 |
| Linux/Linuxgeneric | >=afe4fd062416b158a8a8538b23adc1930a9b88dc <cf398f67d9caa71af3b9fb9319058b22fe6b524e || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <fd63409b669f9951f1cc6b02486a5254103800d1 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <d16dac3925be95ad46e986d4b139c9898b6e227f || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <f6b3e3848a5fca63438984acd6d9eceac80814c1 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <e35acd56f244d94355f9ab237c2ecc8fba5e6f04 || >=afe4fd062416b158a8a8538b23adc1930a9b88dc <709f34f7c28dc4dd6c40343d101850f11e172312 | cf398f67d9caa71af3b9fb9319058b22fe6b524e, fd63409b669f9951f1cc6b02486a5254103800d1, d16dac3925be95ad46e986d4b139c9898b6e227f, f6b3e3848a5fca63438984acd6d9eceac80814c1, e35acd56f244d94355f9ab237c2ecc8fba5e6f04, 709f34f7c28dc4dd6c40343d101850f11e172312 |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
In the Linux kernel, the following vulnerability has been resolved: net/sched: fq: add overflow bounds to quantum and initial quantum fq_init() computes quantum = 2 * psched_mtu() and initial_quantum = 10 * psched_mtu() with no overflow check. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return 0x80000000; the 2 * and 10 * multiplications wrap to 0 in 32-bit arithmetic, so q->quantum == 0. Then in fq_dequeue() the credit-refill loop adds 0 to f->credit (which stays <= 0) and goto begin loops forever under the qdisc lock, creating a soft lockup. Clamp psched_mtu() to [1, 1 << 20] before multiplying so the product cannot wrap, then cap the result at 1 << 20, matching the bound already enforced on TCA_FQ_QUANTUM in fq_change(). Conditions to recreate the bug: a device whose MTU (plus hard_header_len) is large enough that 2 * psched_mtu() wraps (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace.
Quoted source text, attributed separately from HOL analysis.